DOE OSTI2020
Ta9O8Ta3O2(TaO)8Ta2O3 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of one Ta2O3 ribbon oriented in the (0, 1, 0) direction; eight TaO ribbons oriented in the (0, 1, 0) direction; one Ta3O2 sheet oriented in the (0, 0, 1) direction; and one Ta9O8 sheet oriented in the (0, 0, 1) direction. In the Ta2O3 ribbon, there are two inequivalent Ta sites. In the first Ta site, Ta is bonded in a T-shaped geometry to three O atoms. There is one shorter (1.90 Å) and two longer (1.94 Å) Ta–O bond length. In the second Ta site, Ta is bonded in a T-shaped geometry to three O atoms. There are a spread of Ta–O bond distances ranging from 1.91–1.95 Å. There are three inequivalent O sites. In the first O site, O is bonded in a linear geometry to two equivalent Ta atoms. In the second O site, O is bonded in a linear geometry to two equivalent Ta atoms. In the third O site, O is bonded in a linear geometry to two Ta atoms. In each TaO ribbon, Ta is bonded in a linear geometry to two equivalent O atoms. Both Ta–O bond lengths are 1.93 Å. O is bonded in a linear geometry to two equivalent Ta atoms. In the Ta3O2 sheet, there are three inequivalent Ta sites. In the first Ta site, Ta is bonded in a single-bond geometry to one O atom. The Ta–O bond length is 1.95 Å. In the second Ta site, Ta is bonded in a 3-coordinate geometry to three O atoms. There are one shorter (1.87 Å) and two longer (2.25 Å) Ta–O bond lengths. In the third Ta site, Ta is bonded in a bent 150 degrees geometry to two equivalent O atoms. There is one shorter (1.94 Å) and one longer (1.99 Å) Ta–O bond length. There are two inequivalent O sites. In the first O site, O is bonded in a linear geometry to two Ta atoms. In the second O site, O is bonded in a rectangular see-saw-like geometry to four Ta atoms. In the Ta9O8 sheet, there are nine inequivalent Ta sites. In the first Ta site, Ta is bonded in a distorted T-shaped geometry to three O atoms. There are a spread of Ta–O bond distances ranging from 2.08–2.14 Å. In the second Ta site, Ta is bonded in a single-bond geometry to one O atom. The Ta–O bond length is 1.99 Å. In the third Ta site, Ta is bonded in a 3-coordinate geometry to three O atoms. There are a spread of Ta–O bond distances ranging from 2.04–2.34 Å. In the fourth Ta site, Ta is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Ta–O bond distances ranging from 2.07–2.40 Å. In the fifth Ta site, Ta is bonded in a distorted rectangular see-saw-like geometry to four O atoms. There are a spread of Ta–O bond distances ranging from 2.06–2.28 Å. In the sixth Ta site, Ta is bonded in a 4-coordinate geometry to four equivalent O atoms. There are a spread of Ta–O bond distances ranging from 2.24–2.69 Å. In the seventh Ta site, Ta is bonded in a 6-coordinate geometry to eight O atoms. There are a spread of Ta–O bond distances ranging from 2.09–2.79 Å. In the eighth Ta site, Ta is bonded in a bent 150 degrees geometry to two equivalent O atoms. There are one shorter (1.96 Å) and one longer (2.05 Å) Ta–O bond lengths. In the ninth Ta site, Ta is bonded in a rectangular see-saw-like geometry to four O atoms. There are a spread of Ta–O bond distances ranging from 2.11–2.23 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a distorted rectangular see-saw-like geometry to four Ta atoms. In the second O site, O is bonded in a 2-coordinate geometry to three Ta atoms. In the third O site, O is bonded in a rectangular see-saw-like geometry to four Ta atoms. In the fourth O site, O is bonded in a rectangular see-saw-like geometry to four Ta atoms. In the fifth O site, O is bonded in a rectangular see-saw-like geometry to four Ta atoms. In the sixth O site, O is bonded in a distorted T-shaped geometry to three Ta atoms. In the seventh O site, O is bonded in a 4-coordinate geometry to six Ta atoms. In the eighth O site, O is bonded in a 6-coordinate geometry to six Ta atoms.